Your solution has complexity of O(N) per single tower, which results in O(m*N) per test-case which unfortunately is not fast enough. One could easily notice, however, that the dp states will be the same for the same K and L and are independent of N, so you can compute the states only for the largest tower (biggest N), thus resulting in O(N) per test-case.

I managed to get AC modifying your code to do just that, so feel free to ask any questions :)

So what your solution will do is calculate the states from 1 to 3, then from 1 to 12, then from 1 to 113, then from 1 to 25714, then from 1 to 88888. However you can instead calculate them just once from 1 to 88888 and then use dp[3], dp[12], dp[113], dp[25714] and dp[88888] to answer your queries. Do you understand what I mean?